Alkylol amine salts of hydroxy fatty acids and process for their preparation



Patented Sept. 7, 1948 ALKYLOL AMINE SALTS F FATTY ACIDS AND PROCESS FOR THEIR PREPARATION Benjamin B. Schaeiler, Upper Darby, Pa., assignor to United States of America as represented by the Secretary of Agriculture No Drawing. Application December 8, 1944, Serial No. 567,295

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. "157) Claims.

1 This application is made-under the act of ,March 3, 1883, as amended by the act of April 30, 1928, and the invention herein described, if patented, may be manufactured and used-by or for the Government of the United States of America for governmental purposes without the payment to me of any royalty thereon.

This invention relates in general to derivatives of hydroxy fatty acids, and more particularly to the preparation of new compounds from hydroxy higher fatty acids, typified as alkylol amine salts of hydroxy higher fatty acids, which are useful as emulsifying agents and stabilizers. In these salts, the nitrogen is pentavalent, being bonded to three hydrogen atoms, to the fatty acid radical through the residual oxygen atom of the hydroxy] group of the carboxyl group, and to a carbon atom which, in turn, is bonded to three groups at least one of which is an alkylol group, the other two groups being hydrogen, alkyl, or alkylog/ The object of this invention is to provide new compounds in the form of alkylol amine salts of hydroxy higher fatty acids,

These compounds are generally useful as surface-active agents, such as emulsifying agents.

The compounds of this invention may be formed by chemical reaction between monohydroxy or polyhydroxy higher fatty acids and hydrated amino compounds, preferably alkylol amines, involving interaction between the amino hydroxyl ion,of the hydrated amino compound and the hydrogen ion of the carboxyl group of said hydroxy fatty acid. "In this chemical reaction, water is formed as a by-product and the resulting compounds are in character alkylol amine salts having highly desirable surface-active properties Th'e hydroxy higher fatty acids suitable for the preparation of these compounds may be obtained from a variety of sources, one of these being oleic acid. To prepare a monohydroxy higher fatty acid, oleic acid is sulfated with concentrated sulfuric acid and subsequently hydrolyzed to yield a mixture of hydroxylated derivatives. The product prepared in this manner is mainly a mixture of monohydroxystearic acids comprising lo-hydroxystearic acid and 9-hydroxystearic acid and their isomers. A material very satisfactory for our purpose can be obtained by one crystallization of the crude hydrolysis product from an inexpensive solvent such as gasoline,

kerosene, petroleum ether, petroleum naphtha or acetone, or a combination of some of these solvents. The 10- hydroxystearic acid and 9'-hydroxystearic acid, which are important constituents present in the product obtained by sulfation and subsequent hydrolysis of oleic acid, may

be designated by the following formulas, respectively:

cmwmm mwnmcoon on CHS(CHZ)QCH(CHQ)1GOO3 Other suitable hydroxy higher fatty acids include the dihydroxystearic acids obtainable from oleic acid by oxidation with various oxidizing agents, among which may be cited hydrogen peroxide in glacial acetic acid, perbenzoic acid, peracetic acid, or aqueous alkaline potassium permanganate. An example of such a dihydroxy fatty acid is 9, lil-dihydroxystearic acid, the formula of which is cmwnmcncmcmncoon H H 7 Still other hydroxy'higher fatty acids which may be used for the preparation of the new compounds include the trihydroxystearic acids obtained by the oxidation and subsequent hydrolysis of castor oil or the fatty acids therefrom. Suitable oxidizing agents for this purpose include hydrogen peroxide in glacial acetic acid, perbenzoic acid, peracetic acid, and aqueous alkaline D6 tassium permanganate. In this case, the hydroxylated derivative is 9,10,12-trl y acid having the following formula:

cmwnnlcnomcncmcm)1c00H on HOH Hydrated amines of the type that are in the scope of this invention react readily with hydroxy higher fatty acids to form alkylol amine salts by the mechanism referred to previously. Among the amino compounds found suitable for this reaction are those known commercially as alkylol amines. They are manufactured by the which, in turn, are, produced by the interaction of nitroparafiins and aldehydes. Specific examples of these compounds are 2-amino-2-methyl-1- propanoi, 2 amino 2 methyl-1,3-propanediol, 2-amino-2-ethyl-1,3-propanediol, 2-amino-2-isopropyl-l,3-propanediol, 2-amino-1-butanol, and 2 amino 2 methylol-1,3-propanediol. These amines, before their use in the invention, are

first hydrated by being dissolved in water, a molecule of water hydrating the amino group (N'Hz) of the amine. The important feature of these hydrated amines is the presence of a reactive amino hydroxyl ion, as well as of one or more hydroxyl groups, the former being necessary for the chemical combination and the latter for the impartation of desirable properties to the products disclosed in this invention. It is to be understood, however, that this invention is not limited to the use of the particular amino compounds named, but includes all amines capable of reacting to form the new compounds referred to herein.

These new compounds are conveniently prepared by adding the hydroxy higher fatty acid to a hot aqueous solution of the amino compound in substantially equal molecular proportions. In this hot water medium the interaction of the reactants takes place very readily and the compounds thus formed may be used directly in aqueous solution in any desired concentration for those applications where this procedure is suitable. In other applications where it may be desirable to use the emulsifier in the dry form, the water may be removed by distillation or evaporation and the product obtained as a white waxlike solid substance readily dispersible in aqueous solution.

The reaction between monohydroxy higher fatty acids and hydrated amino compounds of the type described forms essentially compounds of the following general formula:

in which Rand B. have the same significance as defined above, and c and d are integers.

The reaction between a trihydroxy higher fatty acid and a hydrated amino compound of the type described forms essentially a compound having the following general formula;

in which R and R have the same significance as in previous type formulas and e and I are integers.

The following examples illustrate the preparation of these new compounds and the manner in which they may be applied in practice.

Example 1 Twenty parts of monohydroxystearic acid (a type of emulsion, 5

4 mixture of 9-hydroxystearic acid, lii-hydeoxystearic acid, and their isomers) were stirred intc a solution of 6 parts of 2-amino-2-methyl-1-propanel in 100 parts of water at about C. When all the monohydroxystearic acid was dissolved,

the water was removed by evaporation on a steam bath and the product, a mixture of monohydroxy tertiary butyl ammonium monohydroxystearates, was obtained as a white, wax-like solid which melted at 52435 C. This material was readily dispersible in water with excellent foaming properties. The pH of a 5% aqueous solution of this product at 25 C. was found to be 8.57.

Products of this type exhibit considerable versatility as eflicient emulsifying agents. They are useful for the preparation'of exceptionally stable water dispersions of natural and mineral waxes, vegetable and mineral oils, water emulsion paints, varnishes, and resins. They are very effective solubilizing agents for making uniform casein emulsions for paint formulations and will also disperse insoluble powders in aqueous medium. Their usefulness further extends to printing inks for pigment wetting and the preparation of water t pe inks.

As an illustrative example of a water-in-oil parts of the salt of monohydroxystearic acid and 2-amino-2-methyl-1-propanol as described above were dissolved in 50 parts of mineral oiiwith stirring and to the hot solution was added slowly 100 parts of hot water. This resulted in a stable emulsion of uniform consistency.

For the preparation of an oil-in-water emulsion, a 10% aqueous solution was made by dissolving 10 parts of the emulsifier in parts of hot water with stirring and then adding 50 parts of 1:1 linseed oil-dammar varnish. This emulsion was stable and showed no signs of breaking on long standing.

Example 2 In the preparation of a casein dispersion 2 parts of this compound were dissolved in 50 parts of water and to the solution were'added with rapid stirring 5 parts of granular casein. Agitation was continued until complete dispersion was accomplished and 0.4 part of formaldehyde (35% solution) was added as a preservative.

Casein water emulsion paint was formulated by adding to the above well-stirred casein dispersion, 2 parts of boiled linseed oil, 2 parts of varnish and 1 part of white spirits. The resulting paint had good brushing and water resistant properties.

A smooth wax dispersion was made using the salt made from monohydroxystearic acid and 2- amino 2 methyl 1,3-propanediol. Thirty-five parts of .paraflin wax (M. P. 5658 C.) and 10 parts of stearic acid were melted together and 5 parts of the salt were stirred into this hot mix- Twenty parts of monohydroxystearic acid (a mixture of 9 -hydroxystearic acid, lo-hydroxystearlc acid, and their isomers) and 8 parts of 2- amino-2-methylol-1,3-propanediol were reacted together to form the corresponding derivative according toathe' procedure described in Exampie 1. The product, a mixture of trihydroxy tertiary butyl ammonium monhydroxystearates,

The pH of a aqueous solution" of this prod ct at C. was found tobe 8.27.

' An aqueous casein dispersion was madeb the" (A procedure described in Example 2. wCasein em 1-- slon paint was formulated by adding to thejcasein water dispersion 2 parts of linseed oil, 2*par'ts o! varnish, 1 part of white spirits, 5 parts of china clay, 5 parts of zinc oxide and 0.1 part of drier. A quick-drying flat, white paint with good brushing and water resistant properties was produced.

Carbon black was easily dispersed in water by the aid of this emulsifying agent. Two and onehalf parts of the product made from monohydroxystearic acid and 2-amino-2-methylol-1,3- propanediol, were dissolved in 50 parts of water and then 5 parts of carbon black were slowly added with vigorous stirring. The carbon black wetted readily, forming a smooth mix. In making dispersions of this type involving insoluble powders, grinding in a ball or colloid mill is desirable.

Example 4 Twenty-one parts of 9,10-dihydroxystearic acid and 8 parts of 2-amino-2-methylol-1,3-propanediol were reacted together following the procedure described in Example 1, forming a waxlike product, trihydroxy tertiary butyl ammonium 9,10-dihydroxystearate, which melted at 89- 92 C. The pH of a 5% aqueous solution of this product at 25 C. was found to be 8.5.

An oil-in-water emulsion was made by addin 50 parts of mineral oil to a solution of 5 parts of this emulsifier in 50 parts of hot water. This point of the wax, thereby vious examples. As an illustration of an oil-inresulted in a stable dispersion of uniform consistency.

Example 5 Twenty parts of 12-hydroxystearic acid and 6 parts of 2-amino-2-methyl-l-propanol were reacted together by the method described in Example 1, forming the corresponding salt, mono- '55 hydroxy tertiary butyl ammonium 12-hydroxystearate. as a wax-like substance melting at 81- 82 C. The pH of a 5% aqueous solution of this product at 25 C. was iound to be 8.7.

This material-was also found effective as an emulsifying agent in the preparation of various emulsions similar to those described in the prewater emulsion,'50 parts of a 5% aqueous solution of this emulsifier were stirred into 50 parts of light mineral spirits (B. P. 102129 C.) forming a dispersion of thick consistency which was capable of being further diluted with water.

Example 6 Twenty-two parts of 9,10,12-trihydroxystearic was a white waxmke solid melting at acid were heated with '7 parts of 2-amino-2- methyl-1,3-propanediol to form the correspond- 'ing salt according to the procedure described in Example 1. The product thus formed, dlhy- ,dr'oxy tertiary butyl ammonium 9, 10, 12-trihydroxystearate, was a white, wax-like solid, readfilydispersible in water.

oil-in-water emulsion was made by adding 50 parts of mineral oil to a solution of 5 parts of this emulsifier in 50 parts of hot water, producing a stable dispersion of uniform consistency.

Having thus described my invention, 1 claim:

1. An alkylol amine salt of a saturated hydroxy higher fatty acid.

2. An alkylol amine salt of hydroxystearic acid.

3. An allq'lol amine salt of monohydroxystearic REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS tertiary butyl ammonium SCI-IAEFTER.

Number Name Date 1,799,824 Kern, et al. 1 Apr. '7, 1931 2,167,347 De Groote et al. July 25, 1939 2,181,534 Martin Nov. 28, 1939 2,280,830 Johnson Apr. 28, 1942 2,411,434 Katzman Nov. 19, 1946 

